Deoxidizer



Patented Dec. 13, 1927.

' UNITED STATES PATENT OFF! CLARENCE J". RODMAN, 0F WILKINSBURG, PENNSYLVANIA, ASSIGNOR TO WESTING- HOUSE ELECTRIC MANUFACTURING COMPANY, A CORPORATION OF' PENNSYL- VANIA.

DEOXIDIZER.

No Drawing.

This invention relates to the removal of oxygen from atmospheres containing the same, and more particularly, to the removal of oxygen from closed containers, such as the tanks of transformers, circuit breakers, oil switches, and the like.

In apparatus of this character, it IS customary to place the transformer body, or the like, within a metal container or tank, and cover the same with a-high grade insulating oil. A space is left above the oil level to permit expansion thereof under normal operating conditions, and there s usually provided means whereby communication is allowed to the outside air in order that upon expansion or contraction of the oil, air may be forced out or drawn in, a-

phenomenon which is known as breathing.

The oxygen in the air, which is breathed by the transformer, gradually reacts w1t h the oil, forming a sludge which is detrimental to the insulating properties thereof. Furthermore, it frequently occurs that there is an are formed in the apparatus which disrupts part of the oil, forming combustible gases which mix with the air above the oil and which may accidentally be united. It has occurred at various times that explosions took place with a consequent loss of the apparatus and injury to the operators.

In order to prevent the detrimental effects of oxygen, it has been proposed to provide an inert atmosphere in the container. One of the means was to provide a material through which all the air necessary for breathing of the transformer shall pass, the material being capable of absorbing the oxygen from the air, thus rendering the atmosphere abovethe oil inert.

My invention relates to such materials, it being among the objects thereof to provide a material for deoxidizing atmospheres which shall be eflective in removing the oxygen, which shall have a longlife and shall not deteriorate on standing.

I have found that certain. metals or mixtures of metals, and alloys in finely divided two metals,

Application filed December 21, 1923. Serial No. 682,075.

These metals, which are lower in the electromotive series than hydrogen, do not dc compose water at ordinary temperatures and only a few of these at higher teu'iperaturos. These metals tarnish or oxidize quite readily in air, and the resulting oxides are practically insoluble in water. These metals possess atomic numbers beginning with copper having an atomic number of 29 and ending essentially with tellurium. having a number of 52, with the exception of one or such as bismuth and lead having atomic numbers of 82 and 81, respectively. The elements in'this group have comparatively low melting points, generally below 650 C. with the exception of copper, which melts at about 1083 C These elements lying within the above limits, unless otherwise stated, subject themselves to a process of rapid corrosion best in the finely divided state; less than 200 mesh works most rapidly, although elements of coarser mesh operate satisfactorily, but the reactivity is correspondingly decreased. This divisibility of material does not hold for metals in the highly porous state Where oxidation maybe facilitated by certain salts in solution, which, when added to other constituents of the deoxygenation material give it a moist or soggy consistency. Many of these elements and oxides or other compounds thereof, are soluble in alkalis.

vIt has been demonstrated that these elements oxidize rapidly in thepresence of monatomic anions, chlorine being suitably adaptedto the process if added as a free alkali chloride, or a strongly electropositive action metal chloride, of which calcium chloride is an example. These elements subect themselves to the action of catalysts in hastening oxidation. Metaloius and carbon acting as catalysts have been found to work well, but other substances having catalytic propensities may be utilized. Organic materials such as powdered starch, flour and even activated, precipitated silica have been found to' hasten the process of deoxygenation.

Although I have described my invention setting forth certain metals and alloys which are particularly desirable for the purpose,

my invention is not limited to the metals named above, as other metals also have the desired properties.

obvious that the function of the metals will proceed to some extent without a catalizer,

atmospheric temperatures but incapable of decomposing water, and a substance capableof catalizingthe action of said metal.

2. Amaterial for deoxidizing atmospheres comprising a metal'capable of oxidizing at atmospheric temperatures butvincapable of d composing Water, and a substance capable For instance, some of the nobler metals may bensed. Although I have mentioned the use of catalizers, it is I Lesaeae of catalizing the action of said metal, both in finely divided form.

3. Amaterial for deoxidizing atmospheres comprising a metal capable of oxidizing at atmospheric temperatures but incapable of decomposing water and a substance containing a monatomic anion capable of catalizing the action of said metal.

4. Amaterialfor deoxidizing atmospheres comprising a metal capable of oxidizlng at atmospherlc temperatures but incapable of decomposing water, and a substance'containing a halogen anion capable of catalizing the action of said metal.

In testimony whereof, I have hereunto subscribed my name this 17th day of De- .cember 1923.

a CLARENCE J. soon. 

